1. Technical Field
The invention relates generally to snowplow blade lift assemblies for mounting on a vehicle, and more particularly to snowplow blade lift assemblies which are releasably mounted on the vehicle.
2. Relation to Prior Art
It is often desirable to provide a snowplow blade lift assembly with a mechanism affording the attachment and detachment of the snowplow blade lift assembly to the vehicle. The vehicle owner may wish to remove the snowplow blade, for example, during times when the need for plowing snow arises infrequently or when the vehicle is used for purposes other than for plowing snow.
Conventional detachable snowplow blade lift assemblies often provide a mounting frame permanently attached to the frame of the vehicle, a plow blade attached to an A-frame which, in turn, can be releasably connected to the mounting frame, and a lift mechanism for the A-frame. The mounting frame of various such snowplow blade lift assemblies is located on the front end of the vehicle generally behind the vehicle's bumper. The A-frame with the attached plow is generally removable from the vehicle, but most commonly the lift mechanism, usually a relatively heavy hydraulic lift unit, remains on the vehicle. Leaving the hydraulic lift unit on the vehicle, when the remainder of the plow assembly is removed, extends exposure of the lift unit to the elements and to possible damage. In addition, the permanently mounted, relatively heavy lift unit places the front of the vehicle under additional loading and can reduce the operational life of the suspension of the vehicle. Also, leaving the relatively heavy hydraulic unit on the vehicle can reduce the fuel efficiency of the vehicle.
There has been proposed assemblies wherein the hydraulic lift unit can be removed from the vehicle upon detachment of the plow and wherein the positions of the plow assembly or support therefore remaining on the vehicle are located substantially behind the bumper. Examples of such detachable snowplow blade lift assemblies are illustrated in U.S. Pat. No. 4,279,084 which issued to Low et al. on Jul. 21, 1981; and U.S. Pat. No. 4,439,939 which issued to Blau on Apr. 3, 1984. These prior proposals, however, have been relatively complicated and/or required numerous assembly and disassembly steps and involved numerous separate parts.
Also, when plowing snow, it is sometimes desirable to push the plowed snow into a pile and to "stack" snow on top of the pile or into a bank of snow. In order to stack snow, the A-frame of the snowplow assembly must be free to pivot upwardly relative to the vehicle so that the snowplow blade attached to the A-frame can rise up the slope of the snow bank. A problem with prior conventional detachable snowplow blade lift assemblies is that the mounting frames and components supported thereby are located in a position which interferes with the free upward movement of the A-frame, thereby diminishing the capacity of the snowplow blade lift assembly to stack snow.
Another problem associated with known snowplow blade lift assemblies is that the attachment and detachment of the assembly to the vehicle can require lifting of the A-frame and the connection of various elements of the snowplow blade lift assembly to a mounting frame. Such lifting, attachment and detachment of the snowplow lift assembly can be cumbersome and difficult.
Accordingly, it is an object of the present invention to provide a detachable snowplow blade assembly, plow, A-frame and lift assembly, which can be attached and detached from the front of a vehicle as a single unit.
It is another object of the present invention to provide a snowplow blade lift assembly that does not require a relatively heavy mounting frame to be permanently attached to the vehicle.
It is another object of the invention to provide a snowplow blade lift assembly which can be attached and detached from a vehicle without cumbersome manual lifting of the A-frame.
A more specific object of this invention is to provide a detachable plow, A-frame and lift assembly which, when detached, removes virtually all structural elements forward of the vehicle's bumper.
It is another object of the invention to provide a snowplow blade lift assembly having the above desirable characteristics and as well as the capacity to stack snow.